Indicate by check mark whether
the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form
20-F ☐ Form40-F ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned,
thereunto duly authorized.

THOMSON REUTERS CORPORATION

(Registrant)

By:

/s/ Marc E. Gold

Name: Marc E. Gold

Title:
Assistant Secretary

Date: May 24, 2018

EXHIBIT INDEX

Exhibit

Number

Description

99.1

Normal Course Issuer Bid Press Release

99.2

Notice of Intention to Make a Normal Course Issuer Bid

EXHIBIT 99.1 - NORMAL COURSE ISSUER BID PRESS RELEASE

Exhibit 99.1

Thomson Reuters Announces Annual Renewal of Normal Course Issuer Bid

TORONTO, May 24, 2018  Thomson Reuters Corporation (TSX / NYSE: TRI) today announced that it has received approval from the Toronto
Stock Exchange (TSX) for the annual renewal of its normal course issuer bid (NCIB).

Under the renewed NCIB, up to 35.5 million common shares (representing
approximately 5% of the companys total outstanding shares) may be repurchased between May 30, 2018 and May 29, 2019.

For its current NCIB that
expires on May 29, 2018, Thomson Reuters previously sought and received approval from the TSX to repurchase up to 36 million common shares. Of this amount, Thomson Reuters has repurchased approximately 12.4 million common shares
through May 17, 2018 for a total cost of approximately US$0.56 billion, representing an average price of US$45.17 per share. Thomson Reuters repurchased the common shares through the facilities of the TSX, the New York Stock Exchange
(NYSE) and other alternative trading systems through its broker.

On May 11, 2018, Thomson Reuters announced that it may buy back up to US$500 million of
its shares prior to the closing of its proposed sale
of a 55% interest in its Financial & Risk business. Repurchases under this new program commenced under the current NCIB and are expected to continue under the renewed NCIB. Through
May 17, 2018, the company has repurchased approximately US$20.6 million of shares under this program. Any NCIB repurchases prior to the closing of the proposed Financial & Risk transaction will reduce the size of a contemplated
post-closing substantial issuer bid/tender offer that Thomson Reuters plans to make to all shareholders after the closing of the transaction. The substantial issuer bid/tender offer may be at a premium to the then-current market price of the
companys shares. Thomson Reuters currently expects to use between US$9 billion and US$10 billion of the estimated US$17 billion of gross proceeds of the transaction to return capital to its shareholders through the substantial
issuer bid/tender offer. The companys principal shareholder (Woodbridge) is expected to participate pro rata in the substantial issuer bid/tender offer.

Under the renewed NCIB, shares may be repurchased in open market transactions on the TSX, the NYSE and/or other exchanges and alternative trading systems, if eligible,
or by such other means as may be permitted by the TSX and/or NYSE or under applicable law, including private agreement purchases if Thomson Reuters receives an issuer bid exemption order in the future from applicable securities regulatory
authorities in Canada for such purchases. The price that Thomson Reuters will pay for common shares in open market transactions will be the market price at the time of purchase or such other price as may be permitted by the TSX. Any private
agreement purchases made under an exemption order may be at a discount to the prevailing market price. In accordance with TSX rules, any daily repurchases (other than pursuant to a block purchase exception) on the TSX under the renewed NCIB are
limited to a maximum of 203,187 shares, which represents 25% of the average daily trading volume on the TSX of 812,749 for the six months ended April 30, 2018 (net of repurchases made by the company during that time period). On May 17,
2018, there were 710,406,559 Thomson Reuters common shares outstanding. Any shares that are repurchased will be cancelled.

From time to time, when Thomson Reuters
does not possess material nonpublic information about itself or its securities, it may enter into a pre-defined plan with its broker to allow for the repurchase of shares at times when Thomson Reuters
ordinarily would not be active in the market due to its own internal trading blackout periods, insider trading rules or otherwise. Any such plans entered into with Thomson Reuters broker will be adopted in accordance with applicable Canadian
securities laws and the requirements of Rule 10b5-1 under the U.S. Securities Exchange Act of 1934, as amended.

Thomson Reuters Announces Annual Renewal of Normal Course Issuer Bid

Page 2 of 2

Decisions regarding any future repurchases will depend on the timing of the closing of the proposed
Financial & Risk transaction and other factors, such as market conditions, share price and other opportunities to invest capital for growth. Thomson Reuters may elect to suspend or discontinue share repurchases at any time, in accordance
with applicable laws.

Thomson Reuters

Thomson Reuters is the
worlds leading source of news and information for professional markets. Our customers rely on us to deliver the intelligence, technology and expertise they need to find trusted answers. The business has operated in more than 100 countries for
more than 100 years. Thomson Reuters shares are listed on the Toronto and New York Stock Exchanges (symbol: TRI). For more information, visit www.thomsonreuters.com.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

Certain statements in
this news release are forward-looking, including the companys plans to repurchase up to US$500 million of its common shares and make a substantial issuer bid/tender offer to its shareholders after the closing of the proposed
Financial & Risk transaction. These forward-looking statements are based on certain assumptions and reflect our companys current expectations. As a result, forward-looking statements are subject to a number of risks and uncertainties
that could cause actual results or events to differ materially from current expectations. There is no assurance that a transaction involving all or part of the F&R business will be completed or that other events described in any forward-looking
statement will materialize. You are cautioned not to place undue reliance on forward-looking statements which reflect expectations only as of the date of this news release. Except as may be required by applicable law, Thomson Reuters disclaims any
obligation to update or revise any forward-looking statements.

This news release does not constitute an offer to purchase, or a solicitation of an offer to
sell, securities of the company, nor is it a substitute for any substantial issuer bid/tender offer or other documents that may be filed by the company with the Canadian securities regulatory authorities or the U.S. Securities and Exchange
Commission.

CONTACTS

MEDIA

David Crundwell

Senior Vice President, Corporate Affairs

+1 646 223 5285

david.crundwell@tr.com

INVESTORS

Frank J. Golden

Senior Vice President, Investor Relations

+1 646 223 5288

frank.golden@tr.com

EXHIBIT 99.2 - NOTICE OF INTENTION TO MAKE A NORMAL COURSE ISSUER BID

Exhibit 99.2

Form: 12

Issuer Name: Thomson Reuters Corporation (Thomson Reuters)

Stock Symbol: TRI

1.

Securities Sought  State the following:

a)

Class(es) of securities subject to the NCIB:

Common Shares of Thomson Reuters (Common
Shares)

b)

Total number of securities:

i)

issued and outstanding: (as of May 17, 2018):

710,406,559 Common Shares

ii)

if applicable, in the total public float: (as of ):

Not applicable

c)

Percentage of securities that may be purchased under the NCIB:

i)

% of issued and outstanding (maximum 5%):

4.99%

ii)

% of the public float, as the case may be (maximum 10%):

Not applicable

d)

Maximum number of securities that may be acquired under the NCIB:

Up to 35,500,000 Common Shares

e)

Number of securities the issuer actually intends to acquire under the NCIB (i.e., not necessarily the maximum):

Up to 35,500,000 Common Shares

f)

Is the issuer an investment fund:

No

i)

If the answer is NO, the average daily trading volume for six months prior to date hereof:

812,749
Common Shares  average daily trading volume on the TSX for the six most recently completed months ended April 30, 2018.

if the issuer does not propose to make the same NCIB for all classes of voting and equity securities, the reasons for so limiting the NCIB:

Not applicable

h)

Whether the securities are going to be cancelled. If such securities are not cancelled, state how such securities will be dealt with:

Any Common Shares that are repurchased will be cancelled.

2.

Duration  State the dates on which the NCIB will commence and terminate. The NCIB may not extend for a period of more than one year from the date on which purchases may commence. (i.e. May 1, 2004 to
April 30, 2005):

The NCIB will commence on May 30, 2018 and will terminate no later than May 29, 2019.

3.

Method of Acquisition State the following:

a)

whether purchases will be effected through the facilities of TSX and identify any other exchanges or market places on which purchases will be made:

Purchases of Common Shares will be effected through the facilities of the TSX, the New York Stock Exchange and/or other exchanges and alternative
trading systems, if eligible, or by such other means as may be permitted by the TSX and/or New York Stock Exchange or under applicable law by a registered investment dealer (or an affiliate of the dealer), including private agreement purchases or
share purchase program agreement purchases if Thomson Reuters receives an issuer bid exemption order in the future from applicable securities regulatory authorities in Canada for such purchases.

b)

whether purchase and payment for the securities will be made by the issuer in accordance with the requirements of TSX:

Purchase and payment for the Common Shares will be made by Thomson Reuters in accordance with the requirements of the TSX and applicable securities
laws.

whether the price that the issuer will pay for any securities acquired by it will be the market price of the securities at the time of acquisition:

The price that Thomson Reuters will pay for the Common Shares in open market transactions acquired by it will be the market price of the Common Shares
at the time of acquisition or such other price as may be permitted by the TSX. Any private agreement purchases made under an exemption order may be at a discount to the prevailing market price.

d)

whether purchases (other than by way of exempt offer) will be made other than by means of open market transactions during the period the NCIB is outstanding:

Thomson Reuters does not presently intend to purchase Common Shares other than by means of open market transactions or private agreement purchases
under an exemption order during the period the NCIB is outstanding.

4.

Consideration Offered  State whether there are any restrictions on the price the offeror is prepared to pay and any other restrictions relating to the NCIB, such as specific funds available, method of
purchasing, etc.:

There are no restrictions on the consideration to be offered by Thomson Reuters under the NCIB and there are no
other restrictions relating to the NCIB. Thomson Reuters and holders of the Common Shares will be responsible for the payment of commissions to their respective brokers through which purchases and sales will be made at the applicable prevailing
rates at the time of purchase.

5.

Reasons for the NCIB  State the purpose or business reasons for the NCIB:

In authorizing
the NCIB, the Thomson Reuters Board believes that the purchase of Common Shares from time to time can be undertaken at prices that make the acquisition of such Common Shares an appropriate use of Thomson Reuters available funds and an appropriate
mechanism for returning capital to its shareholders.

6.

Valuation  State whether there has been any appraisal or valuation of the issuer to the best knowledge of the directors or officers of the issuer, after reasonable enquiry, regarding the issuer, its
material assets or securities prepared within the two years preceding the date of the notice, together with a statement of a reasonable time and place at which such appraisal or valuation, or a copy thereof, may be inspected. For this purpose, the
phrase appraisal or valuation means both an independent appraisal or valuation and a material non-independent appraisal or valuation. If there has been such an appraisal or valuation, include a summary of such
appraisal or valuation:

The directors and officers of Thomson Reuters, after reasonable enquiry, have no knowledge of any appraisal
or valuation regarding Thomson Reuters, its material assets or securities, prepared within the last two years preceding the date of this notice.

Previous Purchases  Where the issuer has purchased securities under a NCIB within the past 12 months, state the following:

a)

method of acquisition:

Purchases of Common Shares were effected through the facilities of the TSX,
the NYSE and other alternative trading systems by TD Securities Inc., a registered investment dealer.

b)

the number of securities sought and approved for purchase:

36,000,000

c)

the number of securities actually purchased:

12,361,870 through
May 17, 2018

d)

the weighted average price paid per security:

US$ 45.17

8.

Persons Acting Jointly or In Concert with the Issuer  Disclose the identity of any party acting jointly or in concert with the issuer:

There are no persons acting jointly or in concert with Thomson Reuters.

9.

Acceptance by Insiders, Affiliates and Associates 

a)

name of every director or senior officer of the issuer who intends to sell securities of the issuer during the course of the NCIB:

No director or senior officer of Thomson Reuters presently intends to sell Common Shares during the course of the NCIB. During the course of this
NCIB, directors and senior officers of Thomson Reuters may from time to time effect such sales of Common Shares as may be necessary or desirable in their personal circumstances and sales of Common Shares by such persons may occur as a result of the
exercise by such persons of outstanding stock options or the vesting of restricted share units or deferred share units.

b)

where their intention is known after reasonable enquiry, the name of every associate of a director or senior officer of the issuer, person acting jointly or in concert with the issuer, or person holding 10% or more of
any class of equity securities of the issuer, who intends to sell securities:

Except as set forth below, to the knowledge of
Thomson Reuters, its directors and senior officers, after reasonable enquiry, (i) no associate of a director or senior officer of Thomson Reuters; (ii) no person acting jointly in concert with Thomson Reuters; and (iii) no person
holding 10% or more of any class of equity securities of Thomson Reuters presently intends to sell Common Shares during the course of this NCIB.

As of May 17, 2018, The Woodbridge Company Limited and other companies affiliated with it
(Woodbridge) beneficially owned 451,050,415 Common Shares, or approximately 63% of the outstanding Common Shares. Other than as disclosed in item 13 below, Woodbridge plans to continue to hold its Common Shares for the long term and
accordingly to maintain its controlling interest in Thomson Reuters. From time to time, Woodbridge disposes of Common Shares in amounts that are not material for liquidity and other reasons and such disposals may occur during the course of this
NCIB. Thomson Reuters and Woodbridge have a protocol in place to ensure that Thomson Reuters is not purchasing Common Shares on the open market on any day when Woodbridge is selling Common Shares.

10.

Benefits from the NCIB  State direct or indirect benefits to any of the persons or companies named in item 9 of selling or not selling securities of the issuer during the course of the NCIB. An answer to
this item is not required where the benefits to such person or company of selling or not selling securities are the same as the benefits to any other securityholder who sells or does not sell:

Not applicable

11.

Material Changes in the Affairs of the Issuer  Disclose any previously undisclosed material changes or plans or proposals for material changes in the affairs of the issuer:

To the knowledge of Thomson Reuters, its directors and senior officers, after reasonable enquiry, there are no undisclosed material changes in the
affairs of Thomson Reuters.

Disclose any significant information regarding the NCIB not disclosed above, including any details regarding the use of put options or forward purchase contracts in conjunction with the NCIB:

From time to time, when Thomson Reuters does not possess material nonpublic information about itself or its securities, it may enter into a pre-defined plan with its broker to allow for the repurchase of Common Shares at times when it ordinarily would not be active in the market due to its own internal trading blackout periods, insider trading rules or
otherwise. Any such plans entered into with Thomson Reuters broker will be adopted in accordance with applicable Canadian securities laws and the requirements of Rule 10b5-1 under the U.S. Securities Exchange
Act of 1934, as amended.

As previously announced, Thomson Reuters currently expects to use between US$9.0 billion and
US$10.0 billion of the estimated US$17.0 billion of gross proceeds of its proposed sale of a 55% interest in its Financial & Risk business (the Financial & Risk Transaction) to provide returns to holders of
Common Shares through a post-closing substantial issuer bid/tender offer. Woodbridge is expected to participate pro rata in the substantial issuer bid/tender offer. Any repurchases under the NCIB prior to the closing of the Financial & Risk
Transaction will reduce the size of the substantial issuer bid/tender offer. The substantial issuer bid/tender offer may be at a premium to the then-current market price of the Common Shares.

14.

Certificate  The undersigned, a director or senior officer of the issuer duly authorized by the issuers board of directors, certifies that this notice is complete and accurate and in compliance with
Section 629 of the TSX Company Manual. This notice contains no untrue statement of a material fact and does not omit to state a material fact that is required to be stated or that is necessary to make a statement not misleading in the
light of the circumstances in which it is made.